/**
* @author AlbertDarren
* @contact 2563491540@qq.com
*/
#include <iostream>
#include <cmath>
using namespace std;

int main_27()
{
    double sum=0.0,term;
    double const PI=acos(-1);
    int i=0;
    do
    {
        term=(double)1/(2*i+1);
        if (i%2==0)
        {
            sum+=term;
        }
        else
        {
            sum-=term;
        }
        ++i;
    } while (term>=1e-6);
    printf("%.6lf\n",sum);
    printf("%.6lf\n",PI/4);
	return 0;
}
